Pilot burner and pilot flame hood therefor

ABSTRACT

A mounting plate having a pilot burner, a pilot flame hood and a thermocouple mounted thereon. The pilot burner is comprised of an orifice fitting having a central bore with a central axis and a nose portion through which gas flows to atmosphere for burning as a pilot flame. The nose portion of the fitting has external threads to facilitate mounting of the orifice fitting in a threaded opening in the mounting plate. The pilot flame hood is comprised of a pair of spaced parallel sidewalls, a rear wall extending between the rear edges of the spaced sidewall and a roof wall extending from the rear wall between the top edges of the sidewalls. The sidewalls, rear wall and roof wall together form a partially enclosed gas/air mixing chamber surrounding the nose portion of the orifice fitting. The pilot flame hood is made from a single metal stamping with the sidewalls, rear wall and roof wall thereof formed integrally with each other. The thermocouple is mounted opposite the open side of the gas/air mixing chamber so that the flame exiting from the gas/air mixing chamber will impinge on the thermocouple.

United States Patent [191 Heyde et al. Jan. 7, 1975 PILOT BURNER AND PILOT FLAME HOOD [57] ABSTRACT THEREFOR A mounting plate having a pilot burner a pilot flame 75 Inventors; J Heyde Franklin; Michael hood and a thermocouple mounted thereon. The pilot Grace, Brentwocd both f Ten burner is comprised of an orifice fitting having a central bore with a central axis and a nose portion [73] Asslgnee: Apcom Franklin through which gas flows to atmosphere for burning as 22] Filed; O 31 1973 a pilot flame. The nose portion of the fitting has external threads to facilitate mounting of the orifice fitting [21] P 411,453 in a threaded opening in the mounting plate. The pilot flame hood is comprised of a pair of spaced parallel [52 0.5. CI. 431/80 sidewalls, a rear Wall extending between the rear edges 511 int. Cl. F23n 5/10 of the spaced sidewall and a roof wall extending from 53 Field f Search 431 7; 99 5 the rear wall between the top edges of the sidewalls.

239 The sidewalls, rear wall and roof wall together form a partially enclosed gas/air mixing chamber surrounding [56] References Cited the nose portion of the orifice fitting. The pilot flame UNITED STATES PATENTS hood is made from a single metal stamping with the 3 078 916 2/963 LOV 1 d 431/80 sidewalls, rear wall and roof wall thereof formed inte 3291l86 12/1966 g i fg 1 X grally with each other. The thermocouple is mounted opposite the open side of the gas/air mixing chamber so that the flame exiting from the gas/air mixing chamber will impinge on the thermocouple.

11 Claims, 3 Drawing Figures PILOT BURNER AND PILOT FLAME HOOD THEREFOR BACKGROUND OF THE INVENTION 1. Field of the Invention This invention refers to the combination of a pilot burner, a pilot flame hood for the burner and a thermocouple.

II. Description of the Prior Art In prior apparatus of this type known to applicant, the pilot flame hood is of relatively complex configuration, generally utilizing smoothly curved walls. The pilot flame hood of the present invention is simple and inexpensive to fabricate and provides certain operational advantages over the prior art, namely, a sharp deflection of the pilot flame to produce a thorough mixing action between the gas and air to thereby insure complete combustion. In addition the pilot flame hood produces a positive flame configuration induced in the direction of the thermocouple, which pattern is relatively unaffected by small variations in gas pressure and different spacial relationships of the hood and burner assembly with respect to a horizontal plane.

SUMMARY OF THE INVENTION A pilot burner and pilot flame hood combination comprising a pilot burner means including an orifice fitting having a central bore with a central axis and a nose portion through which gas flows to atmosphere for burning as a pilot flame. The pilot flame hood is comprised of a pair of spaced parallel sidewalls, a rear wall extending between the rear edges of the spaced sidewalls and a roof wall extending from the rear wall between the top edges of the sidewalls. The sidewalls, rear wall and roof wall together form a partially enclosed gas/air mixing chamber surrounding the nose portion of the orifice fitting. The rear wall of the hood angles over the central axis of the orifice fitting and the roof wall angles upwardly from the top of the rear wall so that the pilot burner flame will extend initially from the orifice nose portion into the gas/air mixing chamber along the central axis of the orifice fitting. The flame will first impinge on the rear wall and is deflected by the rear wall toward the roof wall where the flame is again deflected by the roof wall outwardly of the gas/air mixing chamber towards an associated device such as a thermocouple.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation view (with parts broken away) of a pilot burner and hood of the present invention;

FIG. 2 is a sectional view taken along line 2-2 of FIG. 1; and

FIG. 3 is a fragmentary perspective view of the pilot burner and hood shown in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings in detail, a combination of this invention is comprised of two basic components, namely, a pilot burner means and a pilot flame hood means 12 for the burner. Pilot burner means 10 is comprised of a replaceable orifice fitting 14 adapted for connection at its lower end to a gas supply line 16. Fitting 14 is provided with a threaded nose portion 18 and a shoulder 20 at the upper end to facilitate mounting of the fitting in a threaded opening 22 in a mounting bracket member 24. The tip portion of nose 18 is tapered as indicated by reference numeral 26. In the embodiment shown in FIG. I the central axis of orifice fitting 14 extends vertically.

Orifice fitting 14 has a central bore 28 through which gas flows to the atmosphere for burning through a small orifice 30 and a larger orifice 32.

Pilot flame hood means 12 is comprised of a pair of spaced vertical sidewalls 34 and 36 and angled rear wall 38 and an angled roof wall 40. It will be noted that roof 40 extends a short distance outwardly beyond the edges of sidewalls 34 and 36. Sidewalls 34 and 36 are provided with mounting flanges 42 and 44, respec tively. Walls 34, 36, 38 together with roof 40 cooperate to form a partially enclosed gas/air mixing chamber 46. In the preferred embodiment hood means 12 is fabricated from a single metal stamping with sidewalls 34, 36 bent at right angles to rear wall 38 and with roof wall 40 bent at an angle of somewhat less than from the plane of rear wall 38. Mounting flanges 42 and 44 are bent at right angles to sidewalls 34 and 38. While the specific shape of hood means 12 can vary to some extent, in the preferred embodiment rear wall 38 is angled about 18 from the vertical and roof wall 40 is angled about 60 from the vertical.

As best shown in FIG. 3, hood I2 is mounted on bracket 24 by attaching flanges 42 and 44 to the top surface of bracket 24 by spot welding or other suitable means.

. A thermocouple 48 of conventional design is mounted on bracket 24 adjacent hood 12 as shown in FIG. 1. The specific structure for mounting the thermocouple on bracket 24 is not a part of the present invention and is thus not described in detail herein.

OPERATION As best shown in FIGS. 1 and 2, the pilot burner flame indicated generally by reference numeral 50 extends horizontally from orifice 32 in burner 10 initially into mixing chamber 46 along the axis of orifice 32 until it impinges on the upper portion of angled rear wall 38 of hood means 12. From rear wall 38 the flame is deflected outwardly and upwardly to the inner surface of roof wall 40 where it is again deflected outwardly and upwardly along the roof surface and then out of chamber 46 towards thermocouple 48. As shown in FIG. 2, as the flame leaves chamber 46, it will curl outwardly beyond the sidewalls 34 and 36 as indicated by reference numerals 52 and 54.

The relatively sharp deflection of the pilot flame by wall 38 and roof 40 provides a thorough mixing action between the gas and air to thus provide complete combustion and incineration of lint, etc. in the surrounding atmosphere. In addition the hood configuration described above produces a positive flame pattern in the direction of thermocouple 48 which pattern is relatively unaffected by small variations in gas pressure and by different spacial relationships of the hood and burner assembly with respect to the horizontal. While the burner and hood as shown in the drawings are positioned vertically with respect to the horizontal, experience has shown that the assembly will operate satisfactorily at angles of up to 90 from the vertical. Finally, it is noted that the spreading out of the flame 50, as indicated at 52 and 54, facilitates ready ignition of gas from another source such as the main gas burner (not shown) of an appliance such as a water heater.

We claim:

1. A pilot burner and a pilot flame hood combination comprising:

a pilot burner means including an orifice fitting having a central bore with a central axis and a nose portion through which gas flows to atmosphere for burning as a pilot flame; and

a pilot flame hood means comprising a pair of spaced parallel sidewalls, a rear wall extending between the rear edges of the spaced sidewalls and a roof wall extending from said rear wall between the top edges of said sidewalls, said sidewalls, rear wall and roof wall together forming a partially enclosed gas- /air mixing chamber surrounding the nose portion of said orifice fitting, said rear wall angling over the central axis of said orifice fitting and said roof wall angling upwardly from the top of said rear wall so that the pilot burner flame will extend initially from said orifice nose portion into the gas/air mixing chamber along said central axis of said orifice fitting until it impinges on the said rear wall and is deflected thereby to said roof wall where the flame is again deflected by said roof wall outwardly of said gas/air mixing chamber.

2. The combination according to claim 1 in which the angular relationship between said central axis of said orifice fitting and said rear wall and roof wall of said pilot flame hood means is such that when the central axis of said orifice fitting extends vertically, said rear wall will be angled about 18 degrees from the vertical and said roof wall will be angled at about 60 from the vertical.

3. A pilot burner and a pilot flame hood according to claim 1 in which said orifice fitting further includes a small orifice and a large orifice in the nose portion thereof through which gas flows from said central bore first through said small orifice and then through said large orifice into said gas/air mixing chamber of said pilot flame hood means.

4. A pilot burner and a pilot flame hood according to claim 1 in which said pilot flame hood means is made from a single metal stamping with said sidewalls, rear wall and roof wall formed integrally with each other.

5. A pilot burner and a pilot flame hood according to claim 4 in which said pilot flame hood means further includes a pair of mounting flanges formed integrally with said sidewalls.

6. A pilot burner and a pilot flame hood according to claim 1 in which said roof wall of said pilot flame hood means extends a short distance outwardly beyond the edges of said sidewalls.

7. A pilot burner, pilot flame hood and thermocouple combination comprising:

a mounting plate means;

a pilot burner means including an orifice fitting having a central bore with a central axis and a nose portion through which gas flows to atmosphere for burning as a pilot flame, said nose portion having external threads to facilitate mounting said orifice fitting in a threaded opening in said mounting plate means;

a pilot flame hood means mounted on said mounting plate means and comprising a pair of spaced parallel sidewalls, a rear wall extending between the rear edges of the spaced sidewalls and a roof wall extending from said rear wall between the top edges of said sidewalls, said sidewalls, rear wall and roof wall together forming a partially enclosed gas/air mixing chamber surrounding the nose portion of said orifice fitting, said rear wall angling over the central axis of said orifice fitting and said roof wall angling upwardly from the top of said rear wall so that the pilot burner flame will extend initially from said orifice nose portion into the gas/air mixing chamber along said central axis of said orifice fitting until it impinges on said rear wall and is deflected thereby to said roof wall, where the flame is again deflected by said roof wall outwardly of said gas/air mixing chamber; and thermocouple means mounted on said mounting bracket means and positioned opposite the open side of said gas/air mixing chamber so that the flame deflected by said roof wall outwardly of said gas/air mixing chamber will impinge on said thermocouple.

8. The combination according to claim 7 in which the angular relationship between said central axis of said orifice fitting and said rear wall and roof wall of said pilot flame hood means is such that when the central axis of said orifice fitting extends vertically, said rear wall will be angled about 18 degrees from the vertical and said roof wall will be angled at about 60 from the vertical.

9. The combination according to claim 7 in which said pilot flame hood means is made from a single metal stamping with said sidewalls, rear wall and roof wall formed integrally with each other.

10. The combination according to claim 9 in which said pilot flame hood means further includes a pair of mounting flanges formed integrally with said sidewalls and attached to said mounting plate means.

11. The combination according to claim 7 in which said roof wall of said pilot flame hood means extends a short distance outwardly beyond the edges of said sidewalls.

223 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,859,034 I Dated January 7, 1975 Inventor) JOHN c. HEYDE and MICHAEL F. GRACE It is certified that error appears in the above-ident1fied patent and that said Letters Patent are hereby corrected as shown below:

Change address of Assignee from "Ill. to -Tenn.

Signed and sealed this 15th day of April 1975.

,Attest:

C MARE- ALL DART? Commissioner of Patents and Trademarks RUTH C. Z-ZASJP-Y Lttesting Ufficer 

1. A pilot burner and a pilot flame hood combination comprising: a pilot burner means including an orifice fitting having a central bore with a central axis and a nose portion through which gas flows to atmosphere for burning as a pilot flame; and a pilot flame hood means comprising a pair of spaced parallel sidewalls, a rear wall extending between the rear edges of the spaced sidewalls and a roof wall extending from said rear wall between the top edges of said sidewalls, said sidewalls, rear wall and roof wall together forming a partially enclosed gas/air mixing chamber surrounding the nose portion of said orifice fitting, said rear wall angling over the central axis of said orifice fitting and said roof wall angling upwardly from the top of said rear wall so that the pilot burner flame will extend initially from said orifice nose portion into the gas/air mixing chamber along said central axis of said orifice fitting until it impinges on the said rear wall and is deflected thereby to said roof wall where the flame is again deflected by said roof wall outwardly of said gas/air mixing chamber.
 2. The combination according to claim 1 in which the angular relationship between said central axis of said orifice fitting and said rear wall and roof wall of said pilot flame hood means is such that when the central axis of said orifice fitting extends vertically, said rear wall will be angled about 18 degrees from the vertical and said roof wall will be angled at about 60* from the vertical.
 3. A pilot burner and a pilot flame hood according to claim 1 in which said orifice fitting further includes a small orifice and a large orifice in the nose portion thereof through which gas flows from said central bore first through said small orifice and then through said large orifice into said gas/air mixing chamber of said pilot flame hood means.
 4. A pilot burner and a pilot flame hood according to claim 1 in which said pilot flame hood means is made from a single metal stamping with said sidewalls, rear wall and roof wall formed integrally with each other.
 5. A pilot burner and a pilot flame hood according to claim 4 in which said pilot flame hood means further includes a pair of mounting flanges formed integrally with said sidewalls.
 6. A pilot burner and a pilot flame hood according to claim 1 in which said roof wall of said pilot flame hood means extends a short distance outwardly beyond the edges of said sidewalls.
 7. A pilot burner, pilot flame hood and thermocouple combination comprising: a mounting plate means; a pilot burner means including an orifice fitting having a central bore with a central axis and a nose portion through which gas flows to atmosphere for burning as a pilot flame, said nose portion having external threads to facilitate mounting said orifice fitting in a threaded opening in said mounting plate means; a pilot flame hood means mounted on said mounting plate means and comprising a pair of spaced parallel sidewalls, a rear wall extending between the rear edges of the spaced sidewalls and a roof wall extending from said rear wall between the top edges of said sidewalls, said sidewalls, rear wall and roof wall together forming a partially enclosed gas/air mixing chamber surrounding the nose portion of said orifice fitting, said rear wall angling over the central axis of said orifice fitting and said roof wall angling upwardly from the top of said rear wall so that the pilot burner flame will extend initially from said orifice nose portion into the gas/air mixing chamber along said central axis of said orifice fitting until it impinges on said rear wall and is deflected thereby to said roof wall, where the flame is again deflected by said roof wall outwardly of said gas/air mixing chamber; and a thermocouple means mounted on said mounting bracket means and positioned opposite the open side of said gas/air mixing chamber so that the flame deflected by said roof wall outwardly of Said gas/air mixing chamber will impinge on said thermocouple.
 8. The combination according to claim 7 in which the angular relationship between said central axis of said orifice fitting and said rear wall and roof wall of said pilot flame hood means is such that when the central axis of said orifice fitting extends vertically, said rear wall will be angled about 18 degrees from the vertical and said roof wall will be angled at about 60* from the vertical.
 9. The combination according to claim 7 in which said pilot flame hood means is made from a single metal stamping with said sidewalls, rear wall and roof wall formed integrally with each other.
 10. The combination according to claim 9 in which said pilot flame hood means further includes a pair of mounting flanges formed integrally with said sidewalls and attached to said mounting plate means.
 11. The combination according to claim 7 in which said roof wall of said pilot flame hood means extends a short distance outwardly beyond the edges of said sidewalls. 